Further to previous posts in praise of moving around rather than too much sitting, here's a link to a Washington Post article which makes the same point.  It's by a teacher who shadowed two pupils for two days, and was shocked by what she learned, not least that "Students sit all day, and sitting is exhausting".
Click here to read the article (there's also an interesting anti-sarcasm message.  Anyone know a teacher that could benefit from taking that on board?)

About twenty years ago, while I was training to be an Alexander Technique teacher, I attended an 'Art of Running' workshop led by Malcolm Balk, a Canadian Alexander Teacher and former Olympic runner.  Now, on the Guardian's website, Malcolm offers advice on how to walk with good technique, in order to transform walking from a task into a healthy pleasure.  "Try and let go of the urgency that pollutes much of our lives and just enjoy the quality of the movement."  Click here to read Malcolm's five steps to walking well.